A lighting system that includes a plurality of light sources may locate circuitry common to all of the light sources, such as a power supply, in a central controller rather than including redundant copies of the circuitry at each light source. A central power supply, for example, may reduce the cost of the lighting system, due to the fewer total components used, as well as reduce the power consumed by the system, allow for smaller and cooler light sources, and provide a more convenient point of access for maintenance or repair. Such a system may distribute a power bus from the central controller to the plurality of light sources, which may be widely distributed across a room, building, or other area.
In addition to distributing power, the central controller may change the brightness, color, or other such property of one or more of the light sources from a single, easily accessible location. Status information, such as temperature, may be sent from the light sources to the central controller, which may automatically adjust a property of the light sources in response to the information or may present the information to a user. The commands to the lights and the information read from the lights, may be sent and received using one or more buses routed, in addition to the power bus, between the central controller and the light sources. More buses may, however, mean more cost added to the system and more difficulty in installing and maintaining the system. Therefore, in some systems, the power bus is also used as a command bus.
Such configurations enable local detection of anomalies, i.e., deviations from proper operating conditions that occur within a lighting module. If the problem can also be corrected locally, e.g., by adjusting the current to a light source or, in some cases, by disabling the light source entirely, then no external measures will be necessary. That is not always possible, of course; correction of a malfunction may require measures beyond the capability of internal circuitry, and indeed, the circuitry handling internal communications may itself be affected by the malfunction.
Accordingly, there is a need for systems and methods that facilitate internal communication within a lighting module to detect and, where possible, correct anomalies as well as externally communicating state information of the lighting module externally to other devices where appropriate.